UPDATE: Though this concept from 1984, of course, would have been much cooler:

An artist’s concept of the interception and destruction of nuclear-armed re-entry vehicles by a space-based electromagnetic railgun. The LTV Aerospace and Defense Co. has demonstrated hypervelocity launch technology in the laboratory that is applicable to a ballistic missile defense system.

Comments

Let’s put it it this way. The WTC attacks probably cost at least $1 trillion (+ another 3 for the Iraq war response). The cost of a successful ‘rogue’ nuclear attack on an American city would be far higher. Against that background, $120B is a bargain.

Like any developing capability; I’m sure there has been some waste, and there certainly have been enough lumps, bumps and dips in the path to where the system is now. Given the immense technical challenge of developing cutting edge tech like this though; the lumps, bumps & dips should be expected. Humans expanding into orbital and near space is inevitable (and desireable); the militarization of it is too. NOT developing a defensive capability to mitigate the real, and ongoing threat of NBC armed ballistic missile attack is criminally negligent. The downside to a successful BM shield, or capability is it does in fact make the option of first use of nukes by us a more real possibility, as we could depend on our ABM defenses to thwart or blunt any retalitation. The end result of a robust ABM capability is likely to be a new arms race of some sort as rivals attempt to circumvent our new ABM defenses.

I think it was ‘worth it’ for the same reason Kristopher gave, but even so there has been some fantastic waste involved. How they could let the contractors screw around for such a long time developing a missile that has a far easier job to do than a 1970s air-to-air missile his an absolute wonder to me. It was a classic case of both Republicans and Democrats working together to rob the US taxpayer blind. One side says it is impossible, the other stakes its future on it being possible. Now let the blank checks begin. It makes me wonder how much longer we will have to endure this procurement system that rewards process (incompetence) over results.